Panel-shaped construction elements

ABSTRACT

A construction element obtained by fastening a reinforcement to an insulating panel, using an adhesive containing one or more mineral binders and/or one or more polymeric binders, and optionally one or more fillers, optionally one or more adjuvants and optionally one or more additives, the reinforcement being embedded partially but not completely in the adhesive.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the national phase filing of international patent application No. PCT/EP2011/070072, filed 14 Nov. 2011, and claims priority of German application number 10 2010 062 061.0, filed 26 Nov. 2010, the entireties of which applications are incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to construction elements and also to their use for producing formwork and built structures.

BACKGROUND OF THE INVENTION

Formwork has a time-honored use within the construction segment, for the erection of built structures. Conventionally, formwork walls made from wood or composites are used. The formwork is usually set up on the building site and filled in with building material, such as concrete. After the concrete has set, the formwork is removed and the unlined, unfinished wall or floor or ceiling is erected. A disadvantage associated with the formwork is the need to acquire—and provide for the duration of the building-site operation—additional auxiliary equipment which does not end up as part of the built structure. Moreover, the putting-up of the formwork, and the prior pretreatment of the formwork with dehesives, such as forming oil, and also the taking-down and subsequent cleaning of the formwork, are associated with considerable cost and inconvenience.

There is therefore a need for more efficient, more flexible, and more universal approaches to the production of built structures, more particularly using prefabricated components. Proposed for this purpose, for example, have been cages made from steel latticework, possibly with the shape and the dimensions of a wall, whose enveloped interior is filled with insulating materials, such as Styropore particles or polyurethane foam. Steel lattice panels of this kind may be joined to one another via the steel lattice, or suspended from a frame. Surfaces and interstices can be rendered and filled using air-placed concrete or mortar. The static properties of such components, however, are limited. A particular disadvantage, though, is that in spite of the extensive use of insulating materials, the insulating properties of the steel lattice panels are unsatisfactory, since the steel of the steel lattice panels joins the inside to the outside of the wall and acts as a cold bridge.

Similarly unsatisfactory insulating properties result from construction elements for which the insulating panels that serve for the insulation of an outer or inner wall are used as formwork walls, fastened by means of metal spacers. These spacers go through the insulating boards. Normally more than ten spacers per square meter are required. The construction elements prefabricated in this way are then filled in, for example, with concrete, producing concrete walls which are insulated by insulating panels on the inside and the outside. As a result, there is no need for the cost and complexity entailed by the separation of the concrete walls from the formwork.

Nevertheless, the spacers act as a cold bridge. Furthermore, the spacers may adversely affect the static qualities of the walls.

Against this background, the object was to provide measures with which the insulating boards typically employed to insulate built structures can be employed as formwork, the intention being that this formwork should remain in the built structure and that the built structures thus obtained should possess improved heat insulation. A further intention is that these measures should positively affect the static qualities of the built structures, and should be flexibly adaptable to any designs of the built structures, in terms of shape, weight or materials that can be used. The intention here was also to enable flexible adaptation of the components to the requirements of the particular site of application, such as, for example, water resistance, water vapor permeability, or mechanical properties. It was also the intention that construction elements of low weight, that is i.e. having low densities, should be made available, allowing the construction elements to be easily transported by individuals even without auxiliary means, such as cranes.

SUMMARY OF THE INVENTION

The invention provides construction elements obtainable by fastening reinforcement with adhesive to insulating panels, the adhesive comprising one or more mineral binders and/or one or more polymeric binders, and optionally one or more fillers, optionally one or more adjuvants and optionally one or more additives, and

the reinforcement being embedded partially but not completely in the adhesive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of an exemplary construction element according to the invention.

FIG. 2 is a cross-sectional view of exemplary formwork employing construction elements according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The insulating panels are based generally on organic or inorganic, natural or synthetic insulating materials. Examples of synthetic insulating materials are plastics materials, such as polystyrene, more particularly expanded or extruded polystyrene, or polyurethane, more particularly polyurethane foams, mineral materials, more particularly mineral fibers, mineral wool, or mineral foams, or bitumen.

Examples of natural inorganic insulating materials are plaster-based or cement-based materials.

Examples of natural organic insulating materials are wood, particularly in the form of wood boards, chipboards, plywood boards, wood fiber boards, plywood, OSB (Oriented Strand Board), grasses or stalks.

Insulating materials in fiber form, such as mineral wool, wood fibers, wood wool, grasses, or stalks, are generally bound using organic or mineral binders, and brought into a panel form. The production of the insulating boards, though, is known to the skilled person.

Insulating boards possess a low thermal conductivity and are suitable accordingly for heat insulation, such as that of built structures, for example. Moreover, the insulating boards have a sound insulation effect. The thermal conductivity of the insulating boards is preferably 0.001 to 60 W/mK, more preferably 0.002 to 5 W/mK, and most preferably 0.004 to 3 W/mK (determined in accordance with DIN 18159P.1 for plastics materials, DIN 18165 for mineral materials, DIN 52128 for bitumen, DIN 18180 for plaster-based systems, DIN 18550 P3 or DIN 1045 for cement-based systems, and DIN 68705 for wood).

The dimensions of the insulating boards may be arbitrary. The insulating boards generally have a width of 20 to 150 cm and a length of 50 to 500 cm. The thickness of the insulating boards is preferably 1 to 50 cm, more preferably 3 to 30 cm, and most preferably 5 to 20 cm. The density of the insulating boards is preferably 5 to 2500 kg/m³, more preferably 10 to 100 kg/m³, and most preferably 15 to 50 kg/m³. Preferably, therefore, the insulating materials have a low density.

The insulating boards may be lined on their top and/or bottom face with an outer material, such as with card, paper, aluminum foil, bitumen, silicate emulsion paint, or blister film, for example. One example of such boards are plasterboards.

It is also possible for two or more insulating boards to be processed to form a laminate. A laminate generally comprises two or more insulating boards which are mounted flatly one above another and fastened to one another. The individual insulating boards in a laminate are fastened typically by adhesive bonding, but alternatively may also be fastened by screwing or other fastening methods. A laminate preferably comprises one or more plasterboard panels and one or more insulating panels based on insulating materials from the group encompassing expanded polystyrene, extruded polystyrene, and mineral wool; or one or more polystyrene panels and one or more insulating panels based on insulating materials from the group encompassing wood wool and mineral wool.

The reinforcement is based generally on organic materials, such as plastics, or inorganic materials, such as metals, more particularly steel, or inorganic fibers, more particularly carbon fiber or glass fibers.

Metals are present preferably in the form of wires, lattice mats or expanded lattices, which are shaped in turn to form a three-dimensional profile—that is, a not purely sheetlike profile.

The metals preferably have a wavy linear or zigzag profile.

The wires preferably have a diameter of 0.1 to 30 mm, more preferably of 1 to 10 mm. Lattice mats may be produced, for example, by joining wires and/or wire meshes.

Inorganic fibers are preferably in the form of nets or woven fabrics.

Plastics may be present, for example, in the form of lattice mats or expanded lattices, shaped as a wavy linear or zigzag profile, or in the form of nets or woven fabrics. Wires, lattice mats or expanded lattices therefore consist in general not exclusively of substantially planar materials, such as linear wires or planar lattice mats or planar expanded lattices.

Examples of suitable mineral binders are cement, more particularly portland cement, aluminate cement, more particularly calcium sulfoaluminate cement, trass cement, slag cement, magnesia cement, phosphate cement, or blast furnace cement, and also mixed cements, filler cements, fly ash, microsilica, slag sand, lime hydrate, white lime hydrate, calcium oxide (unslaked lime), and gypsum. Preference is given to portland cement, aluminate cement, and slag cement, and also mixed cements, filler cements, lime hydrate, white lime hydrate, or gypsum.

Also preferred are adhesives which comprise at least two mineral binders. In one particularly preferred embodiment the adhesives comprise aluminate cement and one or more further mineral binders. Preference is given to using 0.01 to 99 parts by weight, more preferably 0.05 to 10 parts by weight, and most preferably 0.1 to 5 parts by weight of aluminate cement, based on the parts by weight of the other mineral binders. The use of aluminate cement results in particularly rapid drying of the adhesives and, in combination with polymeric binders, to effective adhesion of the adhesives to the insulating boards and to the reinforcement, especially metals.

In another preferred embodiment of the adhesives, binders employed are exclusively mineral binders—in other words, no polymeric binders. In a likewise preferred embodiment of the adhesives, binders employed are exclusively polymeric binders—that is no mineral binders. With particular preference, however, the adhesives comprise one or more mineral binders and one or more polymeric binders.

Examples of suitable polymeric binders are polyurethanes, polyesters, vinyl esters, polyepoxides, or polyamides, or, preferably, polymers based on ethylenically unsaturated monomers.

The polymers based on ethylenically unsaturated monomers are based for example on one or more ethylenically unsaturated monomers selected from the group encompassing vinyl esters, (meth)acrylic esters, vinylaromatics, olefins, 1,3-dienes, and vinyl halides, and optionally further monomers copolymerizable therewith.

Examples of suitable vinyl esters are those of carboxylic acids having 1 to 15 C atoms. Preference is given to vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurate, 1-methylvinyl acetate, vinyl pivalate, and vinyl esters of α-branched monocarboxylic acids having 9 to 11 C atoms, as for example VeoVa9® or VeoVa10® (trade names of Resolution). Particularly preferred is vinyl acetate.

Examples of suitable monomers from the acrylic ester or methacrylic ester group are esters of unbranched or branched Alcohols having 1 to 15 C atoms. Preferred methacrylic esters or acrylic esters are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, and 2-ethylhexyl acrylate. Particularly preferred are methyl acrylate, methyl methacrylate, n-butyl acrylate, tert-butyl acrylate, and 2-ethylhexyl acrylate.

Preferred vinylaromatics are styrene, methylstyrene, and vinyltoluene. Preferred vinyl halide is vinyl chloride. The preferred olefins are ethylene and propylene, and the preferred dienes are 1,3-butadiene and isoprene.

Optionally it is possible as well for 0 to 10 wt. %, based on the total weight of the monomer mixture, of auxiliary monomers to be copolymerized. Preference is given to using 0.1 to 5 wt % of auxiliary monomers. Examples of auxiliary monomers are ethylenically unsaturated monocarboxylic and dicarboxylic acids, preferably acrylic acid, methacrylic acid, fumaric acid, and maleic acid; ethylenically unsaturated carboxamides and carbonitriles, preferably acrylamide and acrylonitrile; monoesters and diesters of fumaric acid and maleic acid such as the diethyl and diisopropyl esters, and also maleic anhydride; ethylenically unsaturated sulfonic acids and/or salts thereof, preferably vinylsulfonic acid and 2-acrylamido-2-methylpropan-sulfonic acid. Further examples are precrosslinking comonomers such as polyethylenically unsaturated comonomers, as for example diallyl phthalate, divinyl adipate, diallyl maleate, allyl methacrylate, or triallyl cyanurate, or postcrosslinking comonomers, as for example acrylamidoglycolic acid (AGA), methylacrylamidoglycolic acid methyl ester (MAGME), N-methylol-acrylamide (NMA), N-methylolmethacrylamide, N-methylolallyl-carbamate, alkyl ethers such as the isobutoxy ether or esters of N-methylolacrylamide, of N-methylolmethacrylamide, and of N-methylolallylcarbamate. Also suitable are epoxide-functional comonomers such as glycidyl methacrylate and glycidyl acrylate. Further examples are silicon-functional comonomers, such as acryloyloxypropyltri(alkoxy)- and methacryloyloxypropyl-tri(alkoxy)-silanes, vinyltrialkoxysilanes, and vinylmethyldialkoxysilanes, with examples of alkoxy groups that may be present being ethoxy and ethoxypropylene glycol ether radicals. Mention may also be made of monomers having hydroxyl or CO groups, examples being methacrylic and acrylic hydroxyalkyl esters such as hydroxyethyl, hydroxypropyl, or hydroxybutyl acrylate or methacrylate, and also compounds such as diacetoneacrylamide and acetylacetoxyethyl acrylate or methacrylate.

Preference is given to one or more polymers selected from the group encompassing vinyl ester homopolymers, vinyl ester copolymers containing one or more monomer units from the group encompassing vinyl esters, olefins, vinylaromatics, vinyl halides, acrylic esters, methacrylic esters, fumaric and/or maleic monoesters or diesters; (meth)acrylic ester homopolymers, (meth)acrylic ester copolymers containing one or more monomer units from the group encompassing methacrylic esters, acrylic esters, olefins, vinylaromatics, vinyl halides, fumaric and/or maleic monoesters or diesters; homopolymers or copolymers of dienes such as butadiene or isoprene, and also of olefins such as ethene or propene, the dienes being possibly copolymerized for example with styrene, with (meth)acrylic esters, or with the esters of fumaric or maleic acid; homopolymers or copolymers of vinylaromatics, such as styrene, methylstyrene, and vinyltoluene; and homopolymers or copolymers of vinylhalogen compounds such as vinyl chloride, the polymers possibly also containing auxiliary monomers.

Particularly preferred are copolymers of one or more vinyl esters with 1 to 50 wt % of ethylene; copolymers of vinyl acetate with 1 to 50 wt % of ethylene and 1 to 50 wt % of one or more further comonomers from the group of vinyl esters having 1 to 12 C atoms in the carboxylic acid radical such as vinyl propionate, vinyl laurate, vinyl esters of alpha-branched carboxylic acids having 9 to 13 C atoms such as VeoVa9, VeoVa10, and VeoVa11; copolymers of one or more vinyl esters, 1 to 50 wt % of ethylene, and preferably 1 to 60 wt % of (meth)acrylic esters of unbranched or branched alcohols having 1 to 15 C atoms, more particularly n-butyl acrylate or 2-ethylhexyl acrylate; and copolymers with 30 to 75 wt % of vinyl acetate, 1 to 30 wt % of vinyl laurate or vinyl esters of an alpha-branched carboxylic acid having 9 to 11 C atoms, and also 1 to 30 wt % of (meth)acrylic esters of unbranched or branched alcohols having 1 to 15 C atoms, more particularly n-butyl acrylate or 2-ethylhexyl acrylate, which will also contain 1 to 40 wt % of ethylene; copolymers with one or more vinyl esters, 1 to 50 wt % of ethylene, and 1 to 60 wt % of vinyl chloride; the polymers may also contain the stated auxiliary monomers in the stated amounts, and the figures in wt % add up to 100 wt % in each case.

Particularly preferred are also (meth)acrylic ester polymers, such as copolymers of n-butyl acrylate or 2-ethylhexyl acrylate, or copolymers of methyl methacrylate with n-butyl acrylate and/or 2-ethylhexyl acrylate; styrene-acrylic ester copolymers with one or more monomers from the group of methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate; vinyl acetate-acrylic ester copolymers with one or more monomers from the group of methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl-acrylate, and optionally ethylene; and styrene-1,3-butadiene copolymers; the polymers may also contain auxiliary monomers in the stated amounts, and the figures in wt % add up to 100 wt % in each case.

Examples of particularly preferred comonomers for vinyl chloride copolymers are α-olefins, such as ethylene or propylene, and/or vinyl esters, such as vinyl acetate, and/or acrylic esters and/or methacrylic esters of alcohols having 1 to 15 C atoms, such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, tert-butyl acrylate, n-butyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl acrylate, and/or fumaric and/or maleic monoesters or diesters such as the dimethyl, methyl-tert-butyl, di-n-butyl, di-tert-butyl, and diethyl esters of maleic acid and/or fumaric acid.

Most preferred are copolymers with vinyl acetate and 5 to 50 wt % of ethylene; or copolymers with vinyl acetate, 1 to 50 wt % of ethylene, and 1 to 50 wt-% of a vinyl ester of α-branched monocarboxylic acids having 9 to 11 C atoms; or copolymers with 30 to 75 wt % of vinyl acetate, 1 to 30 wt % of vinyl laurate or vinyl ester of an alpha-branched carboxylic acid having 9 to 11 C atoms, and also 1 to 30 wt % of (meth)acrylic esters of unbranched or branched alcohols having 1 to 15 C atoms, which also contain 1 to 40 wt % of ethylene; or copolymers with vinyl acetate, 5 to 50 wt % of ethylene, and 1 to 60 wt % of vinyl chloride.

The most preferred copolymers are also vinyl chloride-ethylene copolymers containing 60 to 98 wt % of vinyl chloride units and 1 to 40 wt % of ethylene units, the figures in wt % being based on the total weight of the copolymer and adding up to 100 wt % in each case. Vinyl chloride-ethylene copolymers of these kinds are known from EP 0 149 098 A2.

The monomer selection and the selection of the weight fractions of the comonomers are made so as to result in a glass transition temperature Tg of −50° C. to +30° C., preferably −40° C. to +10° C., more preferably −30° C. to 0° C. The glass transition temperature Tg of the polymers can be determined in a known way by means of Differential Scanning calorimetry (DSC). The Tg may also be calculated approximately in advance by means of the Fox equation. According to Fox T. G., Bull. Am. Physics Soc. 1, 3, page 123 (1956): 1/Tg=x1/Tg1+x2/Tg2+ . . . +xn/Tgn, where xn stands for the mass fraction (wt %/100) of the monomer n, and Tgn is the glass transition temperature, in kelvins, of the homopolymer of the monomer n. Tg values for homopolymers are listed in Polymer Handbook, 2nd Edition, J. Wiley & Sons, New York (1975).

The polymers based on ethylenically unsaturated monomers may be prepared by bulk or solution polymerization processes or, preferably, emulsion or suspension polymerization processes. The emulsion or suspension polymerization is carried out generally in an aqueous medium—as described in DE-A 102008043988, for example. The polymers in this case are obtained in the form of aqueous dispersions. For the polymerization it is possible to use the common protective colloids and/or emulsifiers, as described in DE-A 102008043988. The protective colloids may be anionic or, preferably, cationic, or more preferably nonionic. Also preferred are combinations of cationic and nonionic protective colloids. Preferred nonionic protective colloids are polyvinyl alcohols. Preferred cationic protective colloids are polymers which carry one or more cationic charges, as described for example in E. W. Flick, Water Soluble Resins—an Industrial Guide, Noyes Publications, Park Ridge, N.J., 1991. Preferred protective colloids are partly or fully hydrolyzed polyvinyl alcohols having a degree of hydrolysis of 80 to 100 mol %, more particularly partly hydrolyzed polyvinyl alcohols having a degree of hydrolysis of 80 to 94 mol % and a Höppler viscosity, in 4% strength aqueous solution, of 1 to 30 mPas (Höppler method at 20° C., DIN 53015). The stated protective colloids are obtainable by means of methods known to the skilled person, and for the polymerization are added generally in an amount of in total 1 to 20 wt %, based on the total weight of the monomers.

As described in DE-A 102008043988, the polymers in the form of aqueous dispersions may be converted into corresponding powders redispersible in water. In that case, in general, a drying aid is used in a total amount of 3 to 30 wt %, preferably 5 to 20 wt %, based on the polymeric constituents of the dispersion. The aforementioned polyvinyl alcohols are preferred as a drying aid. Examples of suitable fillers are silica sand, finely ground quartz, finely ground limestone, calcium carbonate, dolomite, clay, chalk, white lime hydrate, talc or mica, granulated rubber, or hard fillers, such as aluminum silicates, corundum, basalt, carbides, such as silicon carbide or titanium carbide, or pozzolanically reacting fillers, such as fly ash, metakaolin, microsilica, and diatomaceous earth. Preferred fillers are silica sand, finely ground quartz, finely ground limestone, calcium carbonate, calcium magnesium carbonate (dolomite), chalk, or white lime hydrate.

Also preferred is the use of lightweight fillers. Lightweight fillers is a term used for fillers with a low bulk density, generally of less than 500 g/l. Typical lightweight fillers, on a synthetic or natural basis, are substances such as hollow glass microbeads, polymers such as polystyrene beads, aluminosilicates, silicon oxide, aluminum silicon oxide, calcium silicate hydrate, silicon dioxide, aluminum silicate, magnesium silicate, aluminum silicate hydrate, calcium aluminum silicate, calcium silicate hydrate, aluminum iron magnesium silicate, calcium metasilicate and/or volcanic slag. The form of the lightweight fillers is not restricted, and it may in particular feature a spherical, platelet-shaped, rodlet-shaped and/or lamellar structure. Preferred lightweight fillers are perlite, Cellite, Cabosil, Circosil, Eurocell, Fillite, Promaxon, Vermex and/or wollastonite, and also polystyrene.

It is also possible to use any desired mixtures of the stated fillers. Preferred mixtures comprise at least two different fillers. Preferred mixtures comprise one or more carbonatic fillers and one or more other fillers. Carbonatic fillers are preferably selected from the group encompassing calcium carbonate, chalk, dolomite, and limestone. Preferred mixtures contain preferably 5 to 60 wt %, more preferably 10 to 50 wt %, and most preferably 20 to 50 wt % of carbonatic fillers, based on the total weight of the fillers employed overall. Using carbonatic fillers allows the mechanical robustness of the adhesives to be increased.

The fillers have diameters of preferably 0.1 μm to 4 mm, more preferably of 1 μm to 2 mm, and most preferably of 1 μm to 1 mm. In one particularly preferred embodiment, the fillers comprise no gravel. Gravel generally has diameters of >2 mm.

Preferred formulations for the adhesives contain

preferably 0.1 to 95 wt %, more preferably 0.1 to 30 wt %, and most preferably 0.5 to 10 wt % of polymeric binders;

preferably 1 to 95 wt %, more preferably 5 to 80 wt %, most preferably 20 to 50 wt % of mineral binders;

preferably 5 to 95 wt %, more preferably 30 to 85 wt %, and most preferably 49 to 75 wt % of fillers;

the figures in wt % are based on the dry weight of the adhesives and add up in total to 100 wt %.

In one preferred embodiment the adhesives comprise as one addition agent one or more plasticizers from the group encompassing casein, lignosulfonates, melamine and polycarboxylates. Plasticizers are also known under the rubrics of leveling, liquefying or flow control agents. Plasticizers are present in the adhesives preferably at 0.01 to 1 wt %, based on the dry weight of the adhesives. Adhesives of these kinds are also referred to as leveling mortars. Leveling mortars lead to construction elements in which the reinforcements are joined particularly firmly to the insulating panels.

In another preferred embodiment, the adhesives comprise as one addition agent one or more thickeners from the group encompassing polysaccharides such as cellulose ethers and modified cellulose ethers, starch ethers, guar gum, xanthan gum, polycarboxylic acids such as polyacrylic acid and partial esters thereof, and also polyvinyl alcohols, which may optionally have been acetylized or hydrophobically modified, casein, and associative thickeners. Thickeners are present in the adhesives preferably at 0.01 to 1 wt %, based on the dry weight of the adhesives. Adhesives of this kind are also known as bonding mortars. The bonding mortars contain preferably <0.005 wt % of plasticizer, based on the dry weight of the bonding mortars.

One customary adjuvant to the adhesives also comprises one or more setting accelerators, such as alkali metal salts or alkaline earth metal salts or aluminum salts of organic or inorganic acids, for example. Preferred setting accelerators are aluminum salts, aluminates, alkali metal silicates, such as waterglass, for example, alkali metal carbonates, or potassium hydroxide. Particularly preferred setting accelerators are aluminum sulfate, alkali metal aluminates such as potassium aluminate, aluminum hydroxides, potassium carbonate, or sulfoaluminates such as calcium sulfoaluminate, for example. Setting accelerators are present in the adhesives preferably at 0 to 2 wt %, more preferably at 0.1 to 1 wt %, and most preferably at 0.1 to 0.5 wt %, based on the dry weight of the adhesives.

Customary additives for the adhesives are water repellents, such as fatty acids or derivatives thereof, such as esters, or silicones. Other customary additives are retardants, such as hydroxycarboxylic acids, or dicarboxylic acids or salts thereof, saccharides, oxalic acid, succinic acid, tartaric acid, gluconic acid, citric acid, sucrose, glucose, fructose, sorbitol, and pentaerythritol. Other common additives are crosslinkers such as metal oxides or semimetal oxides, more particularly boric acid or polyborates, or dialdehydes, such as glutaraldehyde; further additives are fibers, such as Kevlar, viscose fibers, polyamide fibers, polyester fibers, polyacrylonitrile fibers, Dralon fibers, polyethylene fibers, polypropylene fibers, polyvinyl alcohol fibers, aramid fibers, or carbon fibers. Mention may also be made of the following: preservatives, film-forming assistants, dispersants, foam stabilizers, defoamers, and flame retardants (e.g., aluminum hydroxide).

Generally speaking, the fraction of additives in the adhesives is in total 0 to 20 wt %, preferably 0.1 to 15 wt %, and more preferably 0.1 to 10 wt %, based in each case on the dry weight of the adhesives.

Generally speaking, water is added to the adhesives before they are applied. The aqueous adhesives obtainable in this way contain preferably 10 to 90 wt % and more preferably 15 to 50 wt % of water, based on the dry weight of the adhesives.

The adhesives are preferably premixed in the form of dry mixes. Dry mixes comprise preferably all of the constituents of the formula in question, apart from water. The adhesives are therefore preferably one-component systems.

The adhesives may also be employed as two-component systems. In two-component systems, the first component comprises one or more aluminate cements, one or more polymeric binders, one or more fillers, optionally one or more addition agents, and optionally one or more additives, and also water. The second component corresponds to the first component, with the difference that in place of aluminate cement there are one or more other mineral binders present. The weight fractions of the individual constituents of the first component and of the second component comply with the figures of the adhesives formula indicated above. The first component and the second component are used in a ratio of 1:3 to 3:1, based in each case on their dry masses. The first and second components can be mixed in the usual mixing equipment. After the two components are mixed, the adhesive solidifies after a few seconds to minutes. The solidification of the adhesives may also be controlled by using setting accelerators. Two-component systems are of advantage not least in the industrial production of the construction elements, when rapid setting or drying times of the adhesives and also a continuous but interruptible operating regime are desired.

Two-component systems are preferred especially when using leveling mortars, i.e., adhesives comprising plasticizer.

The production of the adhesives is not tied to any particular procedure or mixing apparatus. Adhesives are obtainable by mixing and homogenizing the individual constituents of the formula in conventional powder mixing equipment, as for example by means of mortar mixers, concrete mixers, or plaster machines or stirrers.

The polymeric binders can be used for example in the form of ready-made dispersion adhesives, of the kind available on the market. The polymers based on ethylenically unsaturated monomers are used preferably in the form of aqueous dispersions or more preferably in the form of powders redispersible in water. The dispersions have a solids content of preferably 1 to 80%, more preferably 5 to 70%, and most preferably 10 to 60%.

To fasten reinforcement to an insulating panel, first the adhesive and then the reinforcement can be applied to the insulating panel. Alternatively the reinforcement can also be laid out onto the insulating panel first, after which the adhesive can be applied. In these ways the construction elements are obtained.

It is possible here for the entire surface of one side of an insulating panel to be provided with a layer of adhesive. Preferably, however, the adhesive is applied in the form of adhesive tracks or adhesive dots to one side of the insulating panels. The adhesives may also be introduced into recesses in the insulating panels. Recesses can be produced by removing material from the insulating panels, by milling out material or cutting out material, for example, or by using a laminate in which the topmost layer does not fully cover the underlying layer or underlying layers, so that the laminate contains a recess. Application of adhesive dots or adhesive tracks to the insulating panels produces construction elements having a relatively low weight, thereby facilitating the handling of the construction elements.

The application thickness of the adhesives (layer of adhesive) is preferably 2 to 80 mm and more preferably 3 to 50 mm. The adhesive dots are preferably approximately circular and have diameters of preferably 20 to 200 mm. The adhesive tracks may have any desired length, depending on the insulating panels. The adhesive tracks are preferably 20 to 200 mm wide. These application thicknesses and the dimensions of the adhesive dots and/or adhesive tracks are advantageous for the mechanical stability and robustness of the construction elements and/or formwork, in conjunction with a low weight of the construction elements and/or formwork.

The reinforcement protrudes preferably 5 to 500 mm, more preferably 50 to 300 mm, and most preferably 100 to 200 mm from the adhesive or layer of adhesive. In other words, the reinforcement is embedded partially but not completely in the adhesive. When the construction elements are used for producing formwork, the reinforcement protruding from the adhesive may serve for the fixing of different construction elements.

Application of the adhesives to the insulating boards is not tied to any particular procedure and may be accomplished, for example, manually or mechanically, using spraying machines, for example.

After the adhesives have cured and/or after the adhesives have solidified as a result of possible drying, the reinforcement is firmly connected to the insulating boards.

Preferred embodiments of the construction elements are shown in FIG. 1. The two construction elements imaged in the figure each consist of an element (1), (2), and (3). In FIG. 1, the two insulating boards (1), which have different thicknesses and are based on different material, each carry an applied layer (2) of adhesive, embedded in which as reinforcement (3) in each case is a metal wire that has a zigzag profile. The reinforcements (3) are therefore embedded partially, but not completely, into the layers (2) of adhesive, and therefore protrude from the layers (2) of adhesive. FIG. 1 is a cross section through the reinforcements (3) of the construction elements.

In one specific embodiment of the construction elements, one or more coatings may be applied to the construction elements, such as one or more renders or paints, for example. Generally speaking, the coating is applied to the side of the insulating panel that is opposite the reinforcement-bearing side of the construction elements. It is possible first to apply the reinforcement to the insulating panels, and then one or more coatings. Alternatively it is also possible first to apply one or more coatings to the insulating panels, and then the reinforcement.

The embodiment of the coatings is basically arbitrary and is guided by the requirements with regard to the construction elements or by the built structures to be produced therewith, and may be adapted, for example, in line with the specific requirements for interior or exterior walls. The requirements are, for example, compressive strengths, capillary water uptake, impact resistance, or water vapor permeability. Among the coating materials that can be used to produce the coatings, the adhesives described above may be included. In the case of industrial production of the construction elements, i.e., in the case of mass production of the construction elements, the coating materials are applied preferably in the form of the above-described two-component systems.

It is also possible to apply installations, such as gas, water, or waste water lines, electric lines, or else hollow pipes to the construction elements.

Additionally provided by the invention is the use of the construction elements of the invention for producing formwork. Formwork is obtainable by arranging construction elements with respect to one another in such a way that reinforcement-bearing sides of the construction elements are opposite one another, and the construction elements are linked to one another via the part of the reinforcement that is not completely embedded in the adhesive. In this way a cavity is produced between the construction elements.

In one preferred embodiment the construction elements are arranged with respect to one another in such a way that the reinforcements (profiles), shaped as wavy lines or zigzag patterns, of mutually opposing reinforcements come close to one another or, preferably, overlap. In this way the construction elements above the reinforcements can be joined to one another in a particularly advantageous way. If the profiles overlap, apertures are formed into which a plug element, as for example a metal rod, preferably a substantially linear metal rod, can be inserted. The metal rod has a diameter of preferably 1 to 50 mm and more preferably of 1.5 to 20 mm. The length of the metal rod may vary, but is guided typically by the dimensions of the insulating panels. In this way the construction elements are joined to one another in a way which is efficient and particularly simple from a technical standpoint. One preferred variant of this embodiment of the formwork is shown in FIG. 2. The two construction elements from FIG. 1, described earlier on above, have been brought toward one another in FIG. 2 to an extent such that the reinforcements (3) of the two construction elements overlap and in this way form apertures into each of which a metal rod (4) has been introduced as a plug element, the two construction elements thus being linked to one another.

FIG. 2 is a cross section through the reinforcements (3) of the formwork.

The reinforcements of different construction elements may also, alternatively, be interlinked with one another in a different way. In a further variant, the linking of construction elements may also take place by way of tongue-and-groove systems.

In a further alternative procedure, the formwork is obtainable by the joining of at least two insulating panels by means of at least one reinforcement, with at least one reinforcement being fastened with adhesive to different insulating panels in such a way that the reinforcement is embedded partly but not fully in the adhesive. In this way, starting from insulating panels, formwork is obtained in one step. This procedure is preferred especially when using plastics materials or insulating materials in fiber form as reinforcements. Insulating materials of these kinds lead to collapsible or foldable formwork, which can then be unfolded again at a later point in time, such as for its application on the building site, for example. Folded-down construction elements can be stored and transported more easily and more efficiently. The formwork can be supplied in prefabricated form to the building site, or can be produced in situ on the building site.

To produce built structures, the cavity present in the formwork between the construction elements is filled in. This can be done using any desired filling material, such as concrete, including lightweight concrete, or mortars, optionally in combination with lightweight fillers. Other filling material used may comprise one or more lightweight fillers. Examples of those suitable for this purpose are the lightweight fillers specified above.

Lightweight fillers preferred as filling materials are expanded clay, expanded glass, perlite, clay, loam, blow-in fillers, such as cellulose fibers or paper scraps, or polymer-bound clay or loam. These lightweight fillers may be bound or unbound. Lightweight fillers are used more particularly for interior walls of built structures.

The bulk densities of the filler materials are typically 10 to 2600 kg/m³, preferably 500 to 2600 kg/m³, more preferably 1500 to 2300 kg/m³, and most preferably 1800 to 2200 kg/m³. The bulk densities of the lightweight fillers are typically 10 to 2500 kg/m³ and more preferably 100 to 1800 kg/m³. Lightweight fillers lead to built structures with a particularly low weight and particularly high heat insulation.

The construction elements and built structures may be furnished with a low weight per unit area, such as preferably from 5 to 100 kg/m², more preferably 5 to 50 kg/m², and most preferably 10 to 25 kg/m².

The entire cavity in the formwork may be filled in with filler material in one step. Alternatively the cavity may also be filled in with filling material in a plurality of steps. In the case of the alternative procedure, the formwork, when using, for example concrete, including lightweight concrete, or mortars as filling material, is exposed to a lower hydrostatic load if the addition of further filling material takes place only when the filling material added before has dried or set.

The filling material introduced also improves the stability and static qualities of the formwork and/or built structures. For further improvement in the stability, the construction elements or formwork may be fastened to the substrate, such as a screed, for example. Suitable for this purpose are customary foam adhesives or mortars, more particularly leveling mortars. In this way it is also possible to compensate for any unevennesses in the substrate. For the lateral fastening of the formwork and/or to prevent slippage of the formwork, the formwork may be placed in recesses made in the ground, or may be supported by means of laterally mounted struts or boards.

Examples of built structures are walls, floors, ceilings, or entire building structures. Larger built structures are obtainable by placing multiple formwork elements alongside one another and filling them in with filling material.

The construction elements and formwork are, surprisingly, very stable with respect to mechanical loads, and so the formwork is not damaged by the introduction of the filling material for the purpose of producing the built structures. The stability of the construction elements can be heightened through the combination of mineral binders and polymeric binders, more particularly polymers based on ethylenically unsaturated monomers.

In view of the low weight and the simple handling of the construction elements of the invention, built structures can be erected by a single person, even without use of auxiliary equipment, such as cranes. Furthermore, the construction elements of the invention are obtainable in a particularly time-efficient and cost-efficient way even by industrial production methods. The built structures of the invention are notable for outstanding insulation properties. The insulating panels that are used for producing the formwork remain in the built structures. The static qualities of built structures can be adapted to the particular technical construction requirements by means of corresponding incorporation of reinforcements. The shape and dimensions of the built structures as well can be configured as desired via the shape, size, and design of the formwork.

The examples which follow serve for detailed elucidation of the invention, and should in any way be considered to constitute a restriction.

Formulations of the Adhesives:

Adhesive 1: Leveling Mortar, One-Component:

180.00 pbw Portland cement CEM I 42.5 R 120.00 pbw High Alumina Cement Fondu Lafarge 400.00 pbw Silica sand H33 (0.063-0.5 mm) 201.30 pbw Omyacarb 20 BG 70.00 pbw Bayer anhydrite 1.00 pbw Agitan P 800 (defoamer) 25.00 pbw Polyvinyl alcohol-stabilized, water- redispersible terpolymer of vinyl acetate, ethylene, and ethylenically unsaturated acrylate 0.50 pbw Tylose H 300 P2 (cellulose ether) 0.50 pbw Polycarboxylate ether (plasticizer) 1.20 pbw Tartaric acid 1.00 pbw Lithium carbonate (Li₂CO₃) 250.00 pbw Water.

Adhesive 2: Leveling Mortar, Two-Component:

The following components A and B were used in a weight ratio of 1:1.

Component A:

250.00 pbw Portland cement CEM I 42.5 R 450.00 pbw Silica sand H33 (0.063-0.5 mm) 272.30 pbw Omyacarb 20 BG 1.00 pbw Agitan P 800 (defoamer) 25.00 pbw Polyvinyl alcohol-stabilized, water- redispersible terpolymer of vinyl acetate, ethylene, and ethylenically unsaturated acrylate 0.50 pbw Tylose H 300 P2 (cellulose ether) 0.50 pbw Polycarboxylate ether (plasticizer) 1.20 pbw Tartaric acid 220.00 pbw Water.

Component B:

250.00 pbw High Alumina Cement Fondu Lafarge 400.00 pbw Silica sand H33 (0.063-0.5 mm) 321.30 pbw Omyacarb 20 BG 1.00 pbw Agitan P 800 (defoamer) 25.00 pbw Polyvinyl alcohol-stabilized, water- redispersible terpolymer of vinyl acetate, ethylene, and ethylenically unsaturated acrylate 0.50 pbw Tylose H 300 P2 (cellulose ether) 0.50 pbw Polycarboxylate ether (plasticizer) 1.20 pbw Tartaric acid 1.00 pbw Lithium carbonate (Li₂CO₃) 220.00 pbw Water.

Adhesive 3: Bonding Mortar, One-Component:

180.00 pbw Portland cement CEM I 42.5 R 120.00 pbw High Alumina Cement Fondu Lafarge 400.00 pbw Silica Sand H33 (0.063-0.5 mm) 201.30 pbw Omyacarb 20 BG 70.00 pbw Bayer anhydrite 1.00 pbw Agitan P 800 (defoamer) 25.00 pbw Polyvinyl alcohol-stabilized, water- redispersible copolymer of vinyl acetate and ethylene 1.20 pbw Tartaric acid (retardant) 1.00 pbw Lithium carbonate (Li₂CO₃) 0.25 pbw Methylcellulose Tylose 10.000 250.00 pbw Water.

Adhesive 4: Bonding Mortar, One-Component:

300.00 pbw Portland cement CEM I 42.5 R 464.00 pbw Silica sand H33 (0.063-0.5 mm) 200.00 pbw Omyacarb 20 BG 1.00 pbw Agitan P 800 (defoamer) 25.00 pbw Polyvinyl alcohol-stabilized, water- redispersible copolymer of vinyl acetate and ethylene 10.00 pbw Calcium formate (accelerator) 0.25 pbw Methylcellulose Tylose 10.000 240.00 pbw Water

Preparation of Adhesives 1 to 4

The constituents of the respective formulation of adhesives 1, 3, and 4, apart from water, were mixed homogeneously in a customary mixer by stirring under standard conditions in accordance with DIN50014. Then the water was added and homogenous mixing took place.

In the case of adhesive 2, components A and B were first prepared separately from one another, in the manner described above, and mixed with the amount of water indicated in each case. After that, component A was mixed with component B.

Production of the Construction Elements

The respective adhesive 1 to 4 was applied uniformly, under standard conditions in accordance with DIN50014 and in a layer thickness of 5 mm, to the base area of a plasterboard panel (dimensions: 250 cm×50 cm×1.5 cm). Then a wire lattice mesh (mesh size of the wire lattice: 5 cm×5 cm; wire diameter: 1.5 mm), which had a zigzag profile, was pressed uniformly into the layer of adhesive until the wire lattice mesh made contact with the plasterboard panel. The wire lattice mesh protruded from the layer of adhesive by about 8 cm. This construction corresponds substantially to the embodiment shown in FIG. 1. After the respective setting time indicated in table 1, under standard conditions in accordance with DIN50014, the adhesive had cured and the respective plasterboard panel construction element was completed.

In the same way, using insulating panels made from expanded polystyrene (EPS panels) (dimensions: 250 cm×50 cm×10 cm), a corresponding EPS construction element was produced with each of adhesives 1 to 4.

Production of the Formwork and Built Structures

A plasterboard panel construction element and also an EPS construction element, both coated with the same one of the aforementioned adhesives, were placed against one another, by the side provided with the wire lattice mesh, in such a way that their zigzag profiles overlapped, the wire lattice meshes of the two different construction elements thus formed apertures. Inserted through into such apertures as a plug element in a vertical direction was a linear metal rod (length: 250 cm; diameter: 2 mm). In total, in parallel with this first metal rod, three further linear metal rods were installed analogously. In this way the plasterboard panel construction element was joined to the EPS construction element, and a formwork element was produced. The cavity between the two construction elements was approximately 16 cm. The weight of the formwork per unit area was 11.3 kg/m². This construction corresponds substantially to the embodiment shown in FIG. 2.

The filling material used for the formwork was a concrete of the following formulation:

370 kg/m³ Portland slag cement CEM II/A-S 42.5 R, 1727 kg/m³ B16 gravel (sieve fraction 0 to 16 mm), 185 kg/m³ Water, 0.75 wt % Melamine sulfonate (plasticizer); figure in wt % is based on cement.

To produce the concrete, first of all the portland slag cement then the B16 gravel were premixed in a forced mixer and then, with the mixer running, water was added and the mixture was mixed for a further three minutes. After a rest time of five minutes, the plasticizer was added, with the mixer running, and the mixer was mixed for one minute thereafter.

The resulting concrete was introduced into the cavity in the aforementioned formwork, in such a way that the entire cavity was filled. After 28 days of storage at 20° C. and 50% relative humidity (dry storage), the concrete had cured and the built structure was completed.

Performance Testing

The EPS construction elements were tested as follows:

The tensile adhesive strength of the reinforcement on the insulating panels of the EPS construction elements was determined in accordance with European standard ETAG 004 subsequent to the storage indicated in Table 1.

The pull-out of the reinforcement from the construction elements was determined in accordance with European standard ETAG 004 subsequent to the storage indicated in Table 1.

The compressive strength was determined using prisms (40 mm×40 mm×160 mm) of the adhesives after 28 days of storage under standard conditions in accordance with DIN EN 206-1, subsequent to the storage indicated in Table 1.

The results of the testing are summarized in Table 1.

TABLE 1 Production and testing of the construction elements: Example 1 2 3 4 Adhesive 1 2 3 4 Setting time [min] 20-30  5-10 20-30 30-60 Tensile adhesive 0.25 0.23 0.25 0.20 strength after dry storage [N/mm²] Pull-out after dry 100 100 100 100 storage [%] Tensile adhesive 0.15 0.12 0.12 0.11 strength after wet storage^(a)) [N/mm²] Pull-out after wet 85 90 80 90 storage^(a)) [%] Compressive strength 40-50 35-45 40-50 35-45 ^(a))Wet storage: following the dry storage, the construction element was stored in water at 23° C. for two days and then stored for two hours at 23° C. and 50% relative humidity. 

1. Construction elements obtainable by fastening reinforcement with adhesive to insulating panels, the adhesive comprising one or more mineral binders and/or one or more polymeric binders, and optionally one or more fillers, optionally one or more adjuvants and optionally one or more additives, and the reinforcement being embedded partially but not completely in the adhesive.
 2. The construction elements of claim 1, characterized in that one or more polymeric binders are selected from the group encompassing polyurethanes, polyesters, vinyl esters, polyepoxides, polyamides and polymers based on ethylenically unsaturated monomers.
 3. The construction elements of claim 1, characterized in that polymeric binders selected are one or more polymers based on one or more ethylenically unsaturated monomers selected from the group encompassing vinyl esters, (meth)acrylic esters, vinylaromatics, olefins, 1,3-dienes, and vinyl halides, and optionally further monomers copolymerizable therewith.
 4. The construction elements of claim 3, characterized in that the polymers are present in the form of aqueous dispersions or in the form of powders redispersible in water.
 5. The construction elements of claim 1, characterized in that the insulating panels have a length of 50 to 500 cm, a width of 20 to 150 cm, and a thickness of 1 to 50 cm.
 6. The construction elements of claim 1, characterized in that the reinforcement is based on organic materials, such as plastics, or on inorganic materials, such as metals or inorganic fibers.
 7. The construction elements of claim 1, characterized in that the adhesives comprise 0.1 to 95 wt % of polymeric binders, 1 to 95 wt % of mineral binders, 5 to 95 wt % of fillers, optionally 0.01 to 1 wt % of plasticizers, optionally 0.01 to 1 wt % of thickeners, optionally one or more further adjuvants, and optionally one or more additives; the figures in wt % are based on the dry weight of the adhesives and add up in total to 100 wt %.
 8. The construction elements of claim 1, characterized in that the application thickness of the adhesives (layer of adhesive) on the insulating panels is 2 to 80 mm.
 9. The construction elements of claim 1, characterized in that the reinforcement protrudes 5 to 500 mm from the layer of adhesive.
 10. The use of the construction elements as claimed in claim 1 for producing formwork.
 11. The use of the construction elements as claimed in claim 1 for producing built structures, such as walls, floors, ceilings, or building structures.
 12. The use of the formwork from claim 10 for producing built structures, such as walls, floors, ceilings, or building structures. 